Duke, a one-time Louisiana (search) state representative, visited Sweden several times in 2004 and this year.

A Swedish man filed a police complaint saying Duke made racist remarks during a speech to neo-Nazis (search) in southern Sweden in February.

A preliminary investigation was dropped because Duke lives in the United States, but chief prosecutor Sven-Erik Alhem said he had ordered police to reopen the case.

"If he has committed a crime, it would be wrong to let him go free," Alhem said.

Duke said the claims were an attack on his freedom of expression and that if he was charged, he would "come back and challenge this."

As an American, "I'm shocked that Sweden apparently has laws against freedom of speech," he told The Associated Press in a telephone interview Tuesday night.

He said he had spoken with "passion and love for European heritage," which he said was under threat from non-European immigration.

"There was nothing hateful about it," he said from Kiev, Ukraine, where he is teaching history and international relations at the private Interregional Academy of Personnel Management (search), known by its Ukrainian acronym, MAUP.

Alhem said police would investigate whether Duke can be tried for "agitation against an ethnic group," a crime punishable in Sweden (search) by up to four years in prison.

If charged, Duke would face arrest if he returns to Sweden, but it was not clear whether Sweden would request him to be extradited.

"That depends on the charges," Alhem said.

Duke won a state House seat in suburban New Orleans in 1989. Distancing himself from overtly racist views, he made the runoff for governor in 1991 but was soundly beaten by Edwin Edwards.

He made a poor showing in 1992 presidential primaries and failed to make the runoff in a later race for Congress.

In 2002, Duke pleaded guilty to bilking his supporters and cheating on his taxes, and spent a year in federal prison, but later denied any wrongdoing.